I bought some of those Variflame primer conversion kits for my Remington 700ML. Because I wanted to use Blackhorn 209. Changed the firing pin and everything. Thought I was good to go. Went to the range where I could go out to a grand. 50 miles away. Got loaded up to fire the first shot with new primer system and fired. Hang fire. Thought I wasn't suppose to get hang fires with this system. Thought, ok I must still have lube in the primer holder or flame channel. Loaded second round. Primer goes off and that's it. Put another primer in. Again primer goes off. Didn't ignite the powder in two primers. I was mad. Traveled 50 miles back home and changed it back to 209 system. And the primer holders was not that easy to get out of the nipple. Seemed like the bolt would nick the primer holder upon firing.
Jason
The difference between the LMRP and the 209's is, heat and pressure. The LRMP is hotter, but the 209 magnum primers have more pressure.
I've shot BH through my Ultimate with LRMP's and although the rifle isn't designed to shoot BH, it ignited it. However.... the bullet MUST be packed tight on the propellant. VERY TIGHT.
I'm no longer shooting BH through the Ultimate, of which its entire design is made to shoot pellets. I ended up with a gas cut breech plug that was replaced. Also, because I was shooting much heavier charges than can be shot from a production rifle, BH turned into a FILTHY mess, clogging up my muzzlebrake and making it twice as hard to clean the rifle.
The T7M pellets do require a swab between shots but, only 3 patches to clean the rifle. I know you want to shoot BH but, if you get a chance, try two (2) T7M pellets in that ignition system. My bet is it will ignite it instantly.